I didn't find anything in the Bitcoin FAQ about how the network shields itself from a flood of valid transactions intended to bring the network to a crawl; basically a DoS type of attack.

I'm sure you guys have thought about this and implemented measures such as accepting only a limited number of transactions/time from each peer, requiring a proof-of-work with each new transaction and dropping transactions with the lowest transaction fee when the queue of pending transactions fills up.

Sorry I don't have time to dig through the forum or the code to find what has been implemented. But having a "Security" section in the FAQ that answers these type of questions would be very helpful to build the confidence of potential users of Bitcoin.